An electrohydrostatic actuator (“EHA”) is a hydraulic actuator run and controlled by its own electrically powered motor-pump assembly. This eliminates the need for a separate hydraulic pump.
In aerospace applications, EHAs are typically a power-by-wire (“PBW”) device operated by aircraft control & power electronics. EHAs may be used to move aerodynamic surfaces such as a steering flap on an aircraft wing, and have been used to replace conventional hydraulic actuator systems.
It is desired to provide an improved electrohydrostatic actuator, an improved hydraulic fluid supply system for an electrohydrostatic actuator, and an improved control valve for such a hydraulic fluid supply system.